A magic cable from another dimension

Hi everyone,

I am currently working on a concept for an interactive art installation. My plan is to build a 10x10m city from cardboard. Participants will get a candle and as they walk through the city sounds will be produced as flame sensors pick up the candle light.

We are talking about 16 flame sensors in total, which are randomly scattered across the city. I would like to combine all the signals from the sensors in a single arduino module which is connected to a laptop with Ableton Live and further a 16-channel-mixer.

My questions are: Are there jumper cables that are 15m long? I was looking on the internet but I couldn't quite find any items and prices. An Arduino Board Mega 2560 A000067 should have enough inputs to do the job, right?

A big thank you at this point for considering my questions! I would sincerely appreciate your help since I am far from being an expert with arduino myself.

Tons of kind regards,


P.S. : Sorry for the misleading title. It was intended to generate attention :)

You could just buy the longest, or even the shortest, and extend them. :o

Buy a reel of 0.5mm wire from RS components or Maplin or Rapid Electronics and make your own.

Two things to watch out for. If the sensors are high impedance then pick-up from nearby electrical equipment may be a problem so use a twisted pair (screened if possible but expensive). You can twist them yourself. Protect your inputs to the Arduino with back to back diodes to the power supply rails. An input resistor (before the diodes) would also help to protect your inputs (if the sensors are high impedance) but may affect the flame sensors operation so choose your input resistors carefully. 100 Ohms are usual. If the flame sensors are low impedance then just use the back to back diodes.

Hope this helps


Thanks a lot Dead_Ard! Really cool feedback. Will definitely try that!

People wandering about a cardboard city carrying open flame candles, what could possibly go wrong?

I would be very doubtful of long cables being used in this fashion, as you are effectively attaching multiple aerials to your board and/or sensors. They will pick up numerous radiated EMF signals along the way from light sources, switching devices (including anything you turn on/off during the visitors walk through the 'building') and even their assorted electrical items such a cell phones.

This problem has already been solved by electronic musicians many years ago. Take a look on the web for the MIDI system specifications - this uses a current-modulated solution rather than voltages, as this is much less susceptible to noise.

Oh, and issue each visitor with a fire extinguisher!


What sensors are we talking about? One cheap solution for cable is to use CAT5, one twisted pair for power,
one for signal back. For long cable runs you’ll need some signal conditioning and EMI suppression at the
receiving end.

Are you expecting to get a fire safety certificate for that installation? LED candle substitutes might be
more reasonable (and easier to detect if you add IR sender circuit)…